Kirk, Helen, Johnstone, Doug, Basu, Shantanu
We analyze a suite of thin sheet magnetohydrodynamical simulations based on the formulation of Basu, Ciolek, Dapp & Wurster. These simulations allow us to examine the observational consequences to a...
Bo Reipurth, John Bally, Josh Walawender, Doug Johnstone, Helen Kirk, Alyssa Goodman
Abstract. The Perseus molecular cloud and its surroundings contain several regions of active or recent star formation lying within about 300 pc of the Sun (see Figure 1). Roughly a dozen OB and over...
Molecular Tracers of Embedded Star Formation in Ophiuchus (2008)
Gurney, Melissa, Plume, Rene, Johnstone, Doug
In this paper we analyze nine SCUBA cores in Ophiuchus using the second-lowest rotational transitions of four molecular species (12CO, 13CO, C18O, and C17O) to search for clues to the evolutionary...
Jorgensen, Jes, Johnstone, Doug, Kirk, Helen, Myers, Philip, Allen, Lori, Shirley, Yancy
We present a census of the population of deeply embedded young stellar objects (YSOs) in the Ophiuchus molecular cloud complex based on a combination of Spitzer Space Telescope mid-infrared data from...
The SCUBA Legacy Catalogue: Continuum Objects Detected by SCUBA (2008)
Di Francesco, James, Johnstone, Doug, Kirk, Helen, MacKenzie, Todd, Ledwosinska, Elizabeth
We present the SCUBA Legacy Catalogues, two comprehensive sets of continuum maps (and catalogues) using data at 850 microns and 450 microns of the various astronomical objects obtained with the...
The SPICA Consortium, Swinyard, Bruce, Nakagawa, Takao, Merken, Patrick, Royer, Pierre, Souverijns, Tim, ...
JCMT/SCUBA Sub-Millimeter Wavelength Imaging of the Integral Shaped Filament in Orion (2007)
Doug Johnstone Canadian, Doug Johnstone, John Bally
We present the first high dynamic range and sensitivity images of the sub-millimeter wavelength continuum emission at 450m and 850m of the "Integral Shaped Filament" in the northern portion...
Dynamical Evolution and Ionization Structure of an Expanding Superbubble: Application to W4 (2007)
Shantanu Basu Doug, Doug Johnstone, P. G. Martin
Recent observations have revealed a superbubble associated with the young stellar cluster OCl 352 near the W4 H II region: a void in H I emission (Normandeau, Taylor, & Dewdney), and a bright...
Doug Johnstone, David Hollenbach, John Bally
We present a model for the photoevaporation of circumstellar disks or dense clumps of gas by an external source of ultraviolet radiation. Our model includes the thermal and dynamic e+ects of 613.6 eV...
Multi-mass Globular Cluster Evolution: Effect on the Mass Function (2007)
Doug Johnstone Canadian, Doug Johnstone
The evolution of multi-mass globular clusters is performed following explicitly the mass lost through two-body evaporation and assuming that equilibrium clusters are represented by multimass King...
Ultraviolet Radiation and Circumstellar Environments (2007)
Doug Johnstone Canadian, Doug Johnstone, Frank Bertoldi
. We discuss the nature of the photoevaporating circumstellar disks in the Orion Nebula. The structure of thermally driven neutral and ionized flow from the disks is derived through a simple,...
Using Numerical Simulations to Gain Insight into the Structure of Superbubbles (2007)
Philip Komljenovic Shantanu, Shantanu Basu, Doug Johnstone
. Recent high resolution observations of Galactic superbubbles have motivated us to re-examine several classes of superbubble models. We compare three classes of hydrodynamic models (the Kompaneets...
John Bally, Ralph S. Sutherl, David Devine, Doug Johnstone
We present new 0.05 00 (22 AU) resolution narrow-band Hubble Space Telescope Planetary Camera images of externally illuminated young stellar objects embedded in the Orion Nebula. We also present 0.02...
Doug Johnstone, Christine D. Wilson, Gerald Moriarty-schieven, Gilles Joncas, Erik Gregersen, Michel Fich
We present results from a survey of the central 700 arcmin 2 region of the Ophiuchi molecular cloud at 850m using the Submillimeter Common-User Bolometer Array (SCUBA) on the James Clerk Maxwell...
Dynamics of Dense Cores in the Perseus Molecular Cloud (2007)
Kirk, Helen, Johnstone, Doug, Tafalla, Mario
We survey the kinematics of over one hundred and fifty candidate (and potentially star-forming) dense cores in the Perseus molecular cloud with pointed N2H+(1-0) and simultaneous C18O(2-1)...
The Gemini Deep Planet Survey -- GDPS (2007)
Lafreniere, David, Doyon, Rene, Marois, Christian, Nadeau, Daniel, Oppenheimer, Ben R., Roche, Patrick F., ...
We present the results of the Gemini Deep Planet Survey, a near-infrared adaptive optics search for giant planets and brown dwarfs around nearby young stars. The observations were obtained with the...
Jorgensen, Jes K., Johnstone, Doug, Kirk, Helen, Myers, Philip C.
We present a census of the population of deeply embedded young stellar objects (YSOs) in the Perseus molecular cloud complex based on a combination of Spitzer Space Telescope mid-IR data from the c2d...
We present results from a 2300 arcmin^2 survey of the Orion A molecular cloud at 450 and 850 micron using the Submillimetre Common-User Bolometer Array (SCUBA) on the James Clerk Maxwell Telescope....
The complete survey of star-forming regions: Phase I data (2006)
Ridge, Naomi A., Di Francesco, James, Kirk, Helen, Li, Di, Goodman, Alyssa A., Alves, João F., ...
We present an overview of data available for the Ophiuchus and Perseus molecular clouds from Phase I of the COMPLETE Survey of Star-Forming Regions. This survey provides a range of data complementary...
The COMPLETE Survey of Star-Forming Regions: Phase I Data (2006)
Ridge, Naomi A., Di Francesco, James, Kirk, Helen, Li, Di, Goodman, Alyssa A., Alves, João F., ...
We present an overview of data available for the Ophiuchus and Perseus molecular clouds from ``Phase I'' of the COMPLETE Survey of Star-Forming Regions. This survey provides a range of data...
The Large and Small Scale Structures of Dust in the Star-Forming Perseus Molecular Cloud (2006)
Kirk, Helen, Johnstone, Doug, Di Francesco, James
We present an analysis of ~3.5 square degrees of submillimetre continuum and extinction data of the Perseus molecular cloud. We identify 58 clumps in the submillimetre map and we identify 39...
Johnstone, Doug, Matthews, Henry, Mitchell, George F.
We present results from a survey of a 1300 arcmin^2 region of the Orion B South molecular cloud, including NGC 2024, NGC 2023, and the Horsehead Nebula (B33), obtained using the Submillimetre...
Multi-Generational Star Formation in L1551 (2005)
Moriarty-Schieven, Gerald H., Johnstone, Doug, Bally, John, Jenness, Tim
The L1551 molecular cloud contains two small clusters of Class 0 and I protostars, as well as a halo of more evolved Class II and III YSOs, indicating a current and at least one past burst of star...
The effect of a strong external radiation field on protostellar envelopes in Orion (2005)
Jorgensen, Jes K., Johnstone, Doug, Van Dishoeck, Ewine F., Doty, Steven D.
We discuss the effects of an enhanced interstellar radiation field (ISRF) on the observables of protostellar cores in the Orion cloud region. Dust radiative transfer is used to constrain the envelope...
Fiege, Jason D., Johnstone, Doug, Redman, Russell O., Feldman, Paul A.
The G11.11-0.12 infrared-dark cloud has a filamentary appearance, both in extinction against the diffuse infrared emission of the Galactic plane and in emission at 850 microns. We use a novel...
An Extinction Threshold for Protostellar Cores in Ophiuchus (2004)
Johnstone, Doug, Di Francesco, James, Kirk, Helen
We have observed continuum emission at lambda = 850 microns over ~4 square degrees of the Ophiuchus star-forming cloud using SCUBA on the JCMT, producing a submillimetre continuum map twenty times...
Photoevaporation of Circumstellar Disks around Young Stars (2004)
Font, Andreea S., McCarthy, Ian G., Johnstone, Doug, Ballantyne, David R.
We examine the ability of photoevaporative disk winds to explain the low-velocity components observed in the forbidden line spectra of low-mass T Tauri stars. Using the analytic model of Shu,...
Johnstone, Doug, Boonman, Annemieke M. S., Van Dishoeck, Ewine F.
Cornerstone molecules (CO, H_2CO, CH_3OH, HCN, HNC, CN, CS, SO) were observed toward seven sub-millimeter bright sources in the Orion molecular cloud in order to quantify the range of conditions for...
Hogerheijde, Michiel R., Johnstone, Doug, Matsuyama, Isamu, Jayawardhana, Ray, Muzerolle, James
We report detection of continuum emission at 850 and 450 micron from disks around four Classical T Tauri stars in the MBM 12 (L1457) young association. Using a simple model we infer masses of...
The G11.11-0.12 Infrared-Dark Cloud: Anomalous Dust and a Non-Magnetic Isothermal Model (2003)
Johnstone, Doug, Fiege, Jason, Redman, R. O., Feldman, P. A., Carey, Sean J.
The G11.11-0.12 Infrared-Dark Cloud has a filamentary appearance, both in absorption against the diffuse 8micron Galactic background, and in emission from cold dust at 850micron. Detailed comparison...
Halting planet migration by photoevaporation from the central source (2003)
Matsuyama, Isamu, Johnstone, Doug, Murray, Norman
The recent discovery of Jupiter-mass planets orbiting at a few AU from their stars compliments earlier detections of massive planets on very small orbits. The short period orbits strongly suggest...
Viscous diffusion and photoevaporation of stellar disks (2002)
Matsuyama, Isamu, Johnstone, Doug, Hartmann, Lee
The evolution of a stellar disk under the influence of viscous evolution, photoevaporation from the central source, and photoevaporation by external stars is studied. We take the typical parameters...
Millimeter-wave Searches for Cold Dust and Molecular Gas around T Tauri Stars in MBM 12 (2002)
Hogerheijde, Michiel R., Jayawardhana, Ray, Johnstone, Doug, Blake, Geoffrey A., Kessler, Jacqueline E.
We report results of a sensitive search for cold dust and molecular gas in the disks around 8 T Tauri stars in the high-latitude cloud MBM 12. Interferometric observations of 3 mm continuum emission...
Galactic Worm 123.4-1.5: A Mushroom-shaped HI Cloud (2000)
Taylor, A. Russ, Mashchenko, Sergey Y., Irwin, Judith A., Basu, Shantanu, Johnstone, Doug
The Dominion Radio Astrophysical Observatory's Synthesis Telescope provides the highest resolution data (1 arcmin and 0.82 km/s) to date of an HI worm candidate. Observed as part of the Canadian...
Using Numerical Simulations to Gain Insight into the Structure of Superbubbles (1999)
Komljenovic, Philip T., Basu, Shantanu, Johnstone, Doug
Recent high resolution observations of Galactic superbubbles have motivated us to re-examine several classes of superbubble models. We compare three classes of hydrodynamic models (the Kompaneets...
Dynamical Evolution and Ionization Structure of an Expanding Superbubble: Application to W4 (1998)
Basu, Shantanu, Johnstone, Doug, Martin, P. G.
Recent observations have revealed a superbubble associated with the young stellar cluster OCl 352 near the W4 H II region: a void in H I emission (Normandeau, Taylor, and Dewdney), and a bright shell...